Furnace door



Dec. 11, 1923; 1,476,907

F. W. MARTIN FURNACE DooR Filed May 21. 1921 4 sheets-sheet 1 Dec. l1 1923.

F. w. MARTIN FURNACE DOOR Filed May 21, 1921 4 Sheets-Sheet 2 Dec. 11,1923. 1,476,907 l F. w. MARTIN v FURNAC; DOOR Filed'May 21. 1 921 4 sheets-sheet s Dec. 1l 1923. i 1,476,907

F. w. MARTIN FURNACE DOOR Filed-May` 2l, 1921 4 Sheets-Sheet 4 Patented Dec. 11, 1923.

UNITED STATES PATENT OFFICE.

FREDERICK W. MARTIN, OF BROOKLYN, NEW YORK, ASSIGNOR T0 FRANKLIN RAIL- WAY SUPPLY COMPANY, `A CORPORATION OF DELAVJARE.

FURNACE DOOR.

Application led May 21, 1921.

To all whom it may con cern.'

Be it. known that I, FREDERICK W. MAR- TIN, a citizen of the United States, residing at Brooklyn, in the county of Kings and State ot New York, have invented certain new and useful Improvements in Furnace Doors, ofwhich the. following is a specitication.

My invention relates :to furnace doors, and more especially to the opening and closing action or mechanism of suoli doors. I aiin t0 make the door'arrangement and mechanism simple, rugged, and compact; convenient and yreliable in use and operation; and relatively inexpensive to How these and other advantages can be secured in. connection with the invention will appear trom my description hereinafter of the best form oic embodiment at present known to nie.

The invention is in some respects specifically applicable to tire doors consisting ot' plates adapted to swing across the door opening,-siicli. as are used especially on steam locomotivea-and I have herein desorihed it with special reference to that use. ln my drawings, I have sho-wn the door plate ulcra on` the door frame structure to one side of the door aperture, so that the door plates swing directly upward` and downward in opening, respectively, but fthe door frame structure can equally well be arranged the other way, with the fulcra above fthe door aperture, so that the door plates shall swing outward and upward to either` side in opening.

In ythe drawings, Fig.v 1 is a iront elevation of a furnace door structure and mechanism conveniently embodying my` invention, the ope-rating toot lever: being partly broken away.

Fig. 2 is a similar view ofthe parts behind the. line 2 2 in Fig. e1- with the operating motor cylinder and its mounting plate removed.

Fig. 3 is a view corresponding to Fig. 2, showing the doors open.

Fig. 41 is a side or end elevation, trom thelett of Fig. 1. y

Fig. 5 shows a transverse section through the doors and door frame, taken as indicated by the line 5 5 in Fig. 1.

Fig. G is a plan view, with certain parts broken away and removed as. indicated by the line 6-G in Fig. l.

manufacture. i

Serial No. 471,410.

Fig. 7 shows an axial mid-section through the motor cylinder and the pressure-control valve casing, on a larger scale than Figs. l 'O' 6.

Fig. 8 shows a horizontal section through the motor cylinder and its mounting plate, taken as indicated by the line 8 8 .in Fig. 7.

F ig. 9 is) a side elevation of the motor cylinder from the right of Fig. 7, showing Ithe pressure-control valve casing in longitudinal section as indicated by the line 9-9 in Fig. 7, and the check valve 47 ope-n. I

Referring to Figs. 1 to 6, it will he seen that the door shown comprises a frame 10 with a door opening 11 therein, and that the door pla-tes or leaves 12, v13 are ulcruined on this traine at one side ot' the door opening, by means of pivot studs or bolts 14, 15 that extend through the lateral arm portions 16, 17 of the door plates. The door plates 12, 13 thus swing apart and together, edgewise, across the door opening; and they are interconnected and thus constrained to move in unison by means of a link 18 which operates across the line of `their fulcra 14, 15 during* ope-ning and closing movements. When closed, the door plates 12, 13 are held against internal pressure (inside the furnace) by an overhang ing lug 19 0n` the frame 10, which oveit laps the -tree ends of both door plates.

For operating the door plates 12, 13, there is provided a fluid-actuated piston 22, arranged to move crosswise ot .the door-plates, in the direction ot the line of the: fulora 14, 15. Compaotness, simplicity, and economy ot space are promoted hy locating the path ot crosswiseinfor-ementl of the piston 22 insido the fulc'ra 14:, 15 rather than outside,-e i. e., to .the side toward the door opening rather than to the side away from it` as here shown. The cylinder 25 for the piston 22 and 'the control-valve casing 26-in a word, the xed structure of the Huid-actuated door motor-are mounted on the front of a supporting plate 27 which is itself mounted on `studs 14:, 15. and the orosswise extending door motor 25. 26 is integrally attached to its lower portion. (5i/ee Figs. (i and 8.) Thus the motor cylinder extends in front of the `door plate 13, which isi permit-ted to 4swing back and forth behind it. The initial opening movement rot this door plate 13 is end of the link and extending ythrough a.

slot 34 in the rear side :of the crosshead guide portion 35 off fthe cylinder 25 and into a lcorresponding guide slot 36 in the doo-r frame 10". (See Fig. 7.) rl`he operating -linlr connection 30, it. will be seen, extends behindthe cylinder 25.

The {luid-actuated piston motor 22, may preferably operate, primarily, to open the door plates 12, 13, which may normallyI be closed by gravity. )Vith the arrangement shown, the upper door plate 12 may be cast. somewhat heavier than the low-er one (or otherwise overweighted) to assure prompt closing; buit if the structure be arranged with the pivots 14,15 above the door opening, this will be unnecessary. Opera-ting fluid under pressnre (e. g., air or steam) is constantly supplied to the valve cavity in the cas-ing 26; and its ent-rance above the piston 22 to depress the same and open the furnace door is controlled bv the conical valve 37 (see Figs. 7 to 9) seated at. 38 at the lower side of the cavity, and constantly urged toward its seat by a helical compression spring 39 above it,-as well as bv fluid pressure. The valve 37 is attached to a plunger rod 40 fitting closely and longitudinally movable in Ithebase of the casing 26, and the rod and the valve can be raised by upward pressure on the protruding lower end of the latter, as by means of a pedal lever 41 fulcrumed ait. 42 between lugs 43 on the Y valve easing 26.

'When the control valve 37 is thus raised, the fluid admitted beneath it passes through a passage 44 in the metal of' the combined cylinder and valve casings 26 to ports 45, 46 leading to the upper end of `the oylinder, the latter above the piston 22,-0 pening the cheek-valve 47 on its way. At the same time tha-t the control valve 37 is raised, the fluid-'tight head portion 48 of the rod 40 overtravels'and closes the exhaustport 49 in the valve casing. When ithe pressure contro-l valve 37 is released and allowed to close again, the exhaust port 49 is opened and the'caylinder 25 vented to the atmosphere. As :or after .the rising piston 22 overtravels the port 45, the check-valve 47 contro-lling the port 46 is closed by and en- 'trape'the-relatively low-pressure fluid 'remaining in the upper end oi the cylinder 2, and this entrapped fluid serves to cushion.

the final closing together of the door plates 12,13.

The movement of' the rod 40 that opens the control valve 37 brings into register with the port 50 (leading to the lower end of the cylinder 25 beneath the piston 22) an annular groove 51 in the rodl 40 w'hirh communicates with the pressure chamber above the valve 37 through holes r2 and 52 and a bore 53 in the rod which bore is plugged at its upper end. The pressure luid thus admitted to the lower side ot the piston 22 cannot overcome the full pressure on the much larger upper side; but when the valve 37 is closed and the upper side of the. piston 22 vented, this tull pressure fluid :it thel lower side of the piston 22 is entra-pped by the descent of the head 43 across the port 50, and its ex pansion aids in closing the door plates 12, 13 against the cushion afforded by the entrapped luid above the piston.

l claim:

l. furnace door comprising a pair of door plates mounted t0 swing apart and together, edgewise, across the door opening, a. link interconnecting said plates and oonstraining them `to move in unison which link operates across the line of their fulcra; and a fluid-actuated piston for operating the. door arranged to move iu :the r irection of the line. of lult-.ra of the plates and operatively connected to one of' said plates.

2. A furnace door comprising a pair oli door plates mounted to swing apart and together, edgewisc, across the door opening, a link interconnecting said plates and constraining them to move in unison which link operates across the line of their fulcra; and a.'lluideact-uated piston for opening the door, with a link-connecting it directly to one of said door plates.

3. A furnace door comprising a pair oli door plates mounted to swine' apart and together, edgewise, across fthe door opening, and interconnected to move in unison; and a vfluitl-actuated piston vfor operating the door arranged to move cross-wise of the door plates inside their tulcra.

4. A. 'furnace door ycomprising a hair of door` plates .mounted to swing lapart and together, edgewise, across the door opening. and interconnected to move in unison; and a fluid motor for operating the door mountted to permitone of the door plates to swing behind it, inside their fulcra.

5. A furnace door comprising a pair of door plates pivoted to swing apart and together, edgewise, across the door opening; a fluid motor for operating the door mounted and arranged for one of the door plates to swing behind it. and for its` piston -to move inside their l'ulcru in substantially the dire-tion ol the initial opening movement o'tf one of the door plates; and linkage means opera-tivelyoonneoting said piston to the door plates, and interconnecting the door plates to swing in unison.

6. A furnace door comprising a pair of door plates mounted to' swing apart and together, edgewise, across the ydoor opening, linkage means interconnecting said plates and const-raining them to move in unison which linkage means operates across the line of Itheir iulcra; a `common over'hanging lug for overlapping the free ends of both door plates to hold 'them against internal pressure when closed; and a Huid motor for operating the door mounted to extend in front of one of the door plates inside their fulera. p

7. A furnace door comprising a pair of door plates mounted t0 swing apart and together, edgewise, across the door opening; a supporting plate mounted and secured on the fulora of said door plates, and extending inward from them; and a fluid-actualted piston motor on the front of said supporting plate extending cr'osswise of the door plates inside their fulcra, with an operating connection from .the piston to one of the door plates inside its fulcrum extending behind said cylinder.

8. A furnace door comprising a pair of door plates mounted to swing apant and together, edgewise, across the door opening, a. link interconnecting said plates and constraining them to move in unison which link` operates across the line of Itheir fulcra; and luicl-actuated piston for operating the oor.

In testimony whereof, I have hereunto signed my name.

FREDERICK W. MARTIN. 

